Roels Blog

Search This Blog

Posts

If you created your own "updatable reports" or your custom version of tabular forms in Oracle Application Express, you'll end up with a query that looks similar to this one:
then you disable the "Escape special characters" property and the result is an updatable multirecord form.
That was easy, right? But now we need to process the changes in the Ename column when the form is submitted, but only if the checkbox is checked. All the columns are submitted as separated arrays, named apex_application.g_f0x - where the "x" is the value of the "p_idx" parameter you specified in the apex_item calls. So we have apex_application.g_f01, g_f02 and g_f03.
But then you discover APEX has the oddity that the "checkbox" array only contains values for the checked rows. Thus if you just check "Jones", the length of g_f02 is 1 and it contains only the empno of Jones - while the other two arrays will contain all (14) rows.
So for processing y…

Recently someone asked me how he could implement multiple authentication schemes for his APEX application. He would like to use (some kind of) Single Sign-on authentication and - as an alternative - an Application Express Authentication. The problem is ... you can only define one Authentication Scheme being "Current" for an application! So how can we solve this issue?

First, we need te be aware that multiple applications can share their authentication by using the same cookie. Thus if you specify "MYCOOKIE" as the Cookie Name in Application A as well as in Application B, you can switch from A to B and back without the need of logging in again. It doesn't matter what Authentication Scheme Type you are using!

Knowing this, we are halfway our solution. We need two Applications. One - the "real" application - using the Application Express Authentication, let's name this one "LAUNCHPAD". And another one using the Single Sign-on Authentication…

Nowadays Docker is everywhere. It is one of the main components of Continuous Integration / Continuous Development environments. That alone indicates Docker has to be seen more as a Software Delivery Platform than as a replacement of a virtual machine.

However ...

If you are running an Oracle database using Docker on your local machine to develop some APEX application, you will probably not move that container is a whole to test and production environments. Because in that case you would not only deliver a new APEX application to the production environment - which is a good thing - but also overwrite the data in production with the data from your development environment. And that won't make your users very excited.
So in this set up you will be using Docker as a replacement of a Virtual Machine and not as a Delivery Platform.
And that's exactly the way Martin is using it as he described in this recent blog post. It is an ideal way to get up and running with an Oracle database …

Until we had the IG, we showed the data in a report (Interactive or Classic). Changes to the data where made by popping up a form page, making changes, saving and refreshing the report upon closing the dialog. Or by clicking an icon / button / link in your report that makes some changes to the data (like changing a status) and ... refresh the report.
That all works fine, but the downsides are: The whole dataset is returned from the server to the client - again and again. And if your pagination size is large, that does lead to more and more network traffic, more interpretation by the browser and more waiting time for the end user.The "current record" might be out of focus after the refresh, especially by larger pagination sizes, as the first rows will be shown. Or (even worse) while you…

For pushing changes from the database to the end user, the regular solution is using websockets. A change in a record is detected - using a trigger or using the CQN (Change Query Notification) feature - and a notification is send to a websocket server. That websocket server broadcasts the notification over a channel to all browsers that are tuned in to that websocket channel. Then the browser reacts to that notification, usually showing an alert or refreshing a report. This trick is described on multiple sites, just Google for "oracle apex websockets" or similar.

So back in the old days, we used that notification in the browser to refresh the (interactive) report. But along comes the Interactive Grid (IG). While he full-refresh mechanism still works for IG, an IG has also the option to refresh just one row.
So wouldn't it be awesome that just the changed row(s) get refreshed upon a change in the database, instead of the whole report? Can we do it ... yes we can!
First i…

(You can read my impression of the first day here)
After a short but good night sleep and an excellent breakfast, Mike Hichwa delivered his second keynote "RAD Challenge: Build a Real World application in 60 minutes”. Although he suffered from connection issues, Mike managed to wow the audience showing the new packaged app "Quick SQL” and the new (currently Cloud-only) “Blueprint” option to create a new application. As JSON is not code (but just a collection of value-attribute pairs), it was really a no-code showcase!
Then it was parallel session time again and I went to see how Christian Rokitta would "Bootstrapify Universal Theme”. The message is: You don’t have to unsubscribe from the Universal Theme (and please don’t!) to create an application that looks totally different from the “regular” APEX applications.
Then I had to deliver my second presentation “Docker for Dummies”. It was aimed at people who might have heard of Docker but really have hardly a clue what …

Last week the SS Rotterdam was the beautiful location of the largest gathering of APEX Developers worldwide. With around 380 (!) attendees a new high was set. And they came from all over the world : I spotted people from The Netherlands, Belgium, Switzerland, Austria, Croatia, Germany, Denmark, Norway, UK, Ireland and the USA. And I even might have missed one or two ….

The event started with a presentation by the “father of APEX”, Mike Hichwa, talking about "Oracle APEX Past, Present and Future”. Of course everyone is curious what the APEX future might bring: Friendly URL’s, automated testing, more JSON, concurrent APEX versions, third party Oauth 2 authentication (think Facebook, Google), APEX app diff and more, a lot more, REST capabilities. And now we have to wait for APEX 5.2 … and that might take a while!
After this keynote, the conference split up in three tracks. After the coffee break I returned to to big theatre where Geertjan Wielenga talked about "Finally Javas…